The proposed research entails the behavioral analysis of the role of auditory cortex by ablation-behavior techniques. The ultimate goal is to discover the psychological functions of auditory cortex which enable humans to respond appropriately to sounds in their enviroment. The short-range goals concern the behavioral assessment of the role of auditory cortex in processing species-specific vocalizations. Specifically, the effect of unilateral and bilateral auditory cortex lesions in monkeys is to be studied by the application of tests designed to assess the psychological as well as the sensory aspects of hearing. By the experimental study of the basic psychological processes in animals, it is hoped to obtain information relevant to human psychological processes and the way in which these capacities fragment as the result of brain damage.